1. Technical Field
The present disclosure relates to an optical element and a display apparatus.
2. Related Art
An optical element in which a plurality of diffraction gratings are arranged in the direction in which the light proceeds is used as a light flux splitting element of an image forming apparatus such as a laser printer or a pupil expansion element of a retina scanning type display apparatus. In order to configure the optical element, a structure in which two translucent substrates in which a diffraction grating is formed are adhered to each other using an adhesive agent in a state of being opposed to each other has been proposed (refer to FIG. 27 in JP-A-2008-197182).
In the optical element, it is necessary that the position of the grating of the diffraction grating is adjusted with high precision so as to extend in a predetermined direction and that the intervals between the diffraction grating are adjusted with high precision. In addition, it is necessary to arrange the diffraction gratings in parallel. However, as the optical element described in JP-A-2008 197182, in the structure in which two substrates are adhered to each other using an adhesive agent in state of being opposed to each other, there is a concern that changes in the intervals between the diffraction gratings, inclination with respect to the off-plane direction, or the like will be generated due to influences such as contraction of the adhesive agent.